Concrete is a widely used building material. In fact, concrete is used more than any other man-made material in the world. Generally speaking, concrete is a composite construction material, composed of cement (commonly Portland cement) or other cementitious materials, and aggregate. Concrete can also include various additives, such as accelerators, retarders, plasticizers, pigments and the like. Concrete solidifies and hardens after mixing with water and placement due to a chemical process known as hydration.
Concrete is typically used in two forms, pre-cast or poured-in-place. For poured-in-place applications, concrete is usually delivered to a construction site by a concrete mixing truck. Concrete mixing trucks usually have a rotatable mixing drum mounted on a truck bed. At a concrete plant, the mixing drum on the truck is charged with a desired amount of the concrete mixture and water. The rotating mixing drum thoroughly combines the concrete constituents and the water and prevents segregation of the aggregate during transportation to a job site so that a relatively homogeneous mixture can be provided.
At a job site, a concrete mixing truck dispenses the concrete mixture from the drum. The concrete mixture is typically conveyed from the mixing drum to the location where the concrete is to be placed through the use of a concrete chute. The concrete chute is usually a U-shaped trough that is pivotally attached to the truck and can be raised and lowered using a hydraulic system. The concrete chute system on a concrete mixing truck usually includes two chute sections pivotally attached to each other so that they can be folded together when the truck is moving and unfolded when needed at a job site. Additional concrete chute sections can be temporarily attached to the chute sections attached to the truck in order to extend the chute a desired distance to reach to location where the concrete is to be placed. Concrete then flows from the drum down the chute due to gravitational forces to a location for placement, such as a concrete form for a basement wall, footing, foundation, floor or other concrete structure.
After the concrete has been dispensed from the mixing drum, the chute is contaminated with the concrete mixture that sticks to the surface of the chute. In the past, a truck operator would clean the concrete from the chute by merely spraying water onto the chute and allowing the water and concrete mixture to fall onto the ground. Recently, however, concerns have grown regarding the potential from contamination of ground water with the concrete contaminated water used to wash the concrete chute. In fact, the Environmental Protection Agency (“EPA”) has established guidelines that waste concrete mix water can no longer be disposed of by washing onto the ground at a job site. The EPA now has guideline, and many state regulations prescribe, that the concrete washed from a concrete chute and the contaminated water used to wash the chute must be stored and transported away from the job site for disposal in an environmentally appropriate manner such that contaminated water will not pose a threat to local ground water.
As a result of these regulations, many different concrete chute washing systems have been developed. U.S. Pat. Nos. 6,155,277; 7,117,995; and 7,594,524 and U.S. patent application Publication Nos. 2006/0000490 and 2010/0232253 and PCT patent application Publication No. WO 2010/027560 illustrate several such concrete chute washing systems (all of which are incorporated herein by reference in their entirety). These systems are undesirable because, inter alia, they are complicated, difficult to assemble and/or operate, inefficient to operate, employ parts that can easily be lost or broken, involve pumps and hoses that can become clogged or break down and/or buckets that may create lifting hazards.
It would therefore be desirable to provide a concrete chute washing system that overcomes the problems associated with the prior art. Specifically, it would be desirable to provide a concrete chute washing system that is relatively easy to assemble and use, is efficient, involves few parts, requires no moving parts or pumps and is durable under the conditions experienced by concrete mixing trucks.